A new vent was drilled in front of the breech mechanism, as the guns were designed to be fired with short friction tubes, the standard means of ignition for artillery pieces at the time.

The conversion was first suggested in 1879 to enable guns fitted in the flank defence of fortifications to be fired much more rapidly.

[2] In this role their targets would have been personnel entering ditches, and the guns were designed to fire case shot only, with ranges of up to about 500 yards.

[2] Because of the nature of the conversion, and the type of ammunition, a service charge of 3lb of black powder was used, as opposed to around three times that amount for a conventional 32-pounder muzzle loading gun.

It was an iron sliding carriage and platform, which enabled the gun to be traversed left and right, as well as run back for storage.